Krait Voltage regulators in the PMIC

In certain MSMs the CPUs are powered using a single supply powered by PMIC ganged regulators
operating in different phases. The krait-regulator-pmic node represents the gang leader and its
associated control, power stage and frequency peripherals.

[First Level Nodes]
Required properties:
- compatible:			Must be "qcom,krait-regulator-pmic".
- spmi-dev-container:	        Specifies that all the device nodes specified
				within this node should have their resources coalesced into a
				single spmi_device.  This is used to specify all SPMI peripherals
				that logically make up the gang leader.
 - #address-cells:		The number of cells dedicated to represent an address
				This must be set to '1'.
 - #size-cells:			The number of cells dedicated to represent address
				space range of a peripheral. This must be set to '1'.

[Second Level Nodes]
Required properties:
- reg:             Specifies the SPMI address and size for this peripheral.
There must be exactly three subnodes qcom,ctl qcom,ps and qcom,freq representing control,
power stage and frequency SPMI peripherals respectively of the gang leader.

Example:
		krait_regulator_pmic: qcom,krait-regulator-pmic {
			spmi-dev-container;
			compatible = "qcom,krait-regulator-pmic";
			#address-cells = <1>;
			#size-cells = <1>;
			status = "disabled";

			qcom,ctl@2000 {
				status = "disabled";
				reg = <0x2000 0x100>;
			};

			qcom,ps@2100 {
				status = "disabled";
				reg = <0x2100 0x100>;
			};

			qcom,freq@2200 {
				status = "disabled";
				reg = <0x2200 0x100>;
			};
		};
